There’s a head-banging, Slipknot-loving horse that’s gone viral for her love for rock and metal, as well as her adverse reaction to country music. A Canadian Quarter Horse named Pretty has become a star on TikTok over the last few weeks after a woman named Autumn Purdy posted a few videos of her head-banging along to some heavy music. In the videos, she can be seen nodding along to the beat both in her stall and out in the pasture. Pretty seems to be a fan of Rammstein, Shinedown, Disturbed, Motorhead, Drowning Pool and Rage Against the Machine, but Purdy told CNN that Slipknot is her favorite…